Selina Concise Class 10 Biology Solution Chapter No. 4- ‘Absorption by Roots : The Processes Involved’ For ICSE Board Students.
PROGRESS CHECK
1) the three primary function of root.
Answer:-the three primary function of roots are –
I.) To give the mechanical support to the plant.
II.) To absorb the water form the soil. To absorb the minerals and nutrients from the soil.
III.) Conduction or transpiration of these materials to the while body parts of plants.
2) Solution:
Answer:-the four purposes for which the plants need water are –
1) Photosynthesis
2) Transpiration
3) Transportation
4) Mechanical stiffness.
3) Solution:
Answer:-
The minerals nutrients mostly used in plants in the plant cells. These elements are the main constituents Of the cell organelles. And these are required for the synthesis of several different compounds and enzymes in the cells.
4) Solution:
Answer:-
The three main characteristics of the roots which make them enable to draw water from the soil are –
1) The enormous surface area of roots
2) The hairs of roots contains cell sap, these has higher water concentration Than the surrounding area hence absorb more water
3) Roots hairs contains thin walls.
PROGRESS CHECK
1) Write True or false.
i)
Answer:-False.
ii)
Answer:-True.
iii)
Answer:-False.
iv)
Answer:-False.
v)
Answer:-True.
vi)
Answer:-
2) Solution:
Answer:-
Diffusion is the process in which the movement of solution occurs from the higher concentration to the region of lower concentrations when these both are directly connected. On the contrary active transport is the movement of the substances from the lower concentrations to the region of higher concentration through a living cell membrane. Hence these are opposite terms.
3) Solution:
Answer:-
Endosmosis is the process in which the inward diffusion of the water takes place through a semipermeable membrane, these causes the swelling of the cell, when the surrounding solution is less concentrated.
4) Solution:
Answer:-
Active transport is the process in which the substances are moved from the region of lower concentrations to the region of higher concentration through a living cell membrane hence it needs Involvement of energy.
5) Solution:
Answer:-
Yes, we can call the passive transport a diffusion process. These both terms are quite similar. There is no input of energy in passive transport. The freely movement of the particles takes place from the region of higher concentration to the region of lower concentrations in both the mechanism.
PROGRESS CHECK
- Name the following:
I) The state of a cell when can not accommodate any more water.
Answer :- Turgidity
II) Pressure of the cell content on the cell wall .
Answer:-Turgor pressure.
III) condition that is opposite to turgid
Answer:-Flaccid
IV) state of a plasmolysed Cell after the re-enter of water.
Answer :- Deplasmolysis.
V) The pressure under which water passes from the living cells of a root into xylem .
Answer:-Roots pressure.
PROGRESS CHECK
1) Solution:
Answer:-in the experiment 4.15 oil was added to prevent the water loss by the process of evaporation.
2) Solution:
Answer:-to find out the conduction of the Xylem vessels we have to take colored dye over there so that the transverse section of the roots will show the difference.
3) Solution:
Answer:- xylem is the part of stem which is located deeper internally.
4) Solution:
Answer:- 4.18 experiment shows that food from the leaves is conducted downward manner through the phloem vessels in the stem. The phloem part was cut and only the xylem vessels was kept. Hence the after some days the upper part of the stem was growing but not the cut- Margin part it is about to die.
Review Questions
A.) MULTIPLE CHOICE TYPE
1) Absorption of water by the plant cell by surface attraction is called :
Answer:-c) Imbibition
Absorption of water by surface attraction is the phenomenon known as imbibition.
Other given phenomenon does not absorb the water by surface attraction.
2) plant cell placed in a certain solution got plasmolysed . What was the kind of solution?
Answer:-c) Hypertonic salt solution
Plasmolysis is the process in which the cytoplasm gets shrink due to removal of the water when it is kept in hypertonic solution.
3) The state of a cell in which the cell in which the cell wall is rigid and stretched by the increases in volume due to the absorption of water is called .
Answer :- b) Turgidity
Turgidity is the process in which the cell absorb more water and due to it the cell wall becomes rigid these type of cell is called turgid cell.
4) Which one of the following is a characteristics NOT related with the suitability of the roots for absorbing water?
Answer:- d) grow downward into the soil.
The upper layer of the soil contains more moisture and nutrients and also the soil is not hard so the absorption of the water becomes easy for roots and as it goes down the rocky part of the earth is starts and hence it is not good for roots because roots cap gets damaged.
5) Movement of the molecules of a substance from the region of their higher concentration to the region of their lower concentration without the involvement of a separating membrane ,is called .
Answer:-b) Diffusion
Diffusion is the process of movement of particles from the higher concentration to the lower concentration without any membrane hence it allows the dissolved particles also the water molecules inside and outside the cell.
6) Osmosis and diffusion are the same except that in osmosis there is
Answer. :-
c) a selectively permeable membrane in between
Osmosis is the process in which the movement of solution takes place from higher concentration to the region of lower concentrations but it has a semipermeable membrane in between because the semipermeable membrane allows only the water content inside the cell and not the dissolved particles.
7) highest water potential (capacity to move out to higher concentrated solution)is that of
Answer:- a) Pure water
Pure water is neutral solution hence it has the highest water potential.
8) The space between the cell wall and plasma membrane in a plasmolysed Cell is filled with
Answer:- d) water
The space is filled with water and not the another fluid because water is neutral solution.
9) What is responsible for guttation?
Answer:-b) Root pressure
Root pressure is responsible for the cell to cell absorption of water and hence it carried out the guttation process through the tip of the leaves. Guttation is the removal of excessive water from the margins of the leaves.
10) The most appropriate characteristics of a Semi-permeable membrane is that.
Answer:- c) It allows a solvent to pass through freely but prevents the passage of the solute.
The semipermeable membrane has work to resist the solute particles or dissolved particles.
B) VERY SHORT ANSWER TYPE
1) Name the following :
a) Solution:
Answer:-
The condition when a cell places in a hypotonic solution is known as Turgidity.
b) Solution:
Answer:-
The process by which intact plants lose water in the form of droplets from leaf margin is known as the process of Guttation.
c) Solution:
Answer:-
Water enters in root hairs by the process of Osmosis.
d) Solution:
Answer:-
The upward conduction of water is functioned by the tissue Xylem.
e) Solution:
Answer:-
The inward movement of the solvent Molecular through the plasma membrane of a cell is known as Endosmosis.
f) Solution:
Answer:-
The process by which molecules distribute themselves evenly within the space they occupy is known as Diffusion.
g) Solution:
Answer:-
The pressure which is responsible for the movement of water molecules across the cortical cell of the root is the Root pressure.
2)
a) Solution:
Answer:-
The pressure exerted by the cell content on the cell wall is the Turgor pressure.
b) Solution:
Answer:-
The condition in which cell content is shrunken is known as Flaccidity.
c) Solution:
Bleeding is the term used for loss ofwater through a cut stem.
3)
a) Solution:
Hypotonic solution is one in which the solution kept outside the cell has lower solute concentration than inside the cell.
b) Solution:
Active transport is one in which the ions outside the roots move in by utilizing Expenditure energy.
c) Solution
The bending movement of certain flower towards the sun and the sleep movement of certain plants at night are examples of Turgor movements.
4) Solution:
a) Answer:-
When placed in a more concentration solution ,the cell contents will shrink.
b) Answer:-
The Pressure by which the water molecules tend to cross the semi-permeable membrane is called osmotic pressure.
c) Answer:-
Active transport is in a direction oppositeto that of diffusion.
5) Match the items in column I with those in column II
Answer:-